Bags made of plastic film such as thin polyethylene film have been used in various sizes Small bags are used in the packaging of sandwiches and the like; larger bags are used for shopping bags and even larger bags are used for containing trash. The present invention is particularly related to draw band bags having a tight closure.
A particularly advantageous closure for such bags includes a draw band or tape constructed from the same polyethylene material. Draw tape bags of this type have been know for several years and are described in various patents such as, for example, U.S. Pat. No. 3,029,853--Piazze. Bags of this type are formed by two pliable plastic sheets joined to one another on three sides and open at a fourth. A tubular hem is provided at the open end of each sheet and contains a pliable thermoplastic strip. A hole intermediate the ends of each hem exposes the strip in the hems allowing them to be pulled through the openings and used as a handle while simultaneously closing the open mouth of the bag. A similar type bag is disclosed in U.S. Pat. No. 4,624,654--Boyd et al. The draw tapes in the bags disclosed in these patents are at the same level in both hems of the bag. Draw tape bags using two tapes at different parallel levels in the bags are disclosed in U.S. Pat. Nos. 3,547,341--Kirkpatrick and 3,738,568--Ruda. In both of these patents the openings for pulling the draw tapes are at the opposite edges of the bag.